Contents

History

It's unknown who the inventor of the spell was and when it was invented. Harry Potter learned this spell in his fourth year, in preparation for the third task of the Triwizard Tournament. Harry also taught this charm to Dumbledore's Army during the 1995-1996 school, so the members would be able to protect themselves when the time came. This was also the subject of a question of the Theory of CharmsO.W.L. in 1996.[1]

Casting and effects

When cast, a bright blue transparent shield appears where the casters wand is pointed providing a protective barrier between themselves and their attacker. The only spell the Shield Charm can't defend against is the Killing Curse, since it's unblockable.[2]

The Shield Charm is a moderately difficult spell. Fred and George Weasley realised that most adult wizards, even those employed by the Ministry of Magic, could not produce a functional Shield Charm (something that not only could Harry Potter accomplish at age fourteen but, also impart to members of the D.A.). They used this to their advantage when marketing their line of protective clothing (hats, cloaks, etc.), upon which permanent Shield Charms were cast.

Harry Potter first learned this spell in his preparations for the Third Task of the Triwizard Tournament, during which his friends Ron Weasley and Hermione Granger shot spells at him so that he could practice shielding himself.[3] Although he later demonstrated an impressive mastery of this technique surpassing that of many Ministry employees, Harry initially had difficulty casting this spell as "Hermione was able to shatter it with a well-placed Jelly-Legs jinx."[2]

Harry once used the charm to defend himself against Professor Snape's Legilimency during Occlumency training, and found himself unexpectedly seeing some of Snape's memories. This was most likely the reason why Snape was using a Pensieve to store his memories, and thus to preserve his privacy. [2]

During his first sixth year Defence lesson, Harry and the other members of his class had to cast this spell non-verbally. When Snape tried to jinx him, Harry instinctively used a Shield Charm (verbally cast) that was powerful enough to throw Snape off his feet, against a table.[4]

Other

Gilderoy Lockhart presumably attempted to demonstrate this charm, or something similar, to Harry during the first meeting of his duelling club, but all he truly wanted was to twirl his wand fancifully, which failed spectacularly, dropping his wand in the process.

Hermione Granger cast the Shield Charm when Harry and Ron got into an argument during their search for the Horcruxes. Hermione cast the shield before they could draw their wands against one another. When Ron subsequently left, Hermione was hampered in trying to follow him and persuade him not to leave by her own shield.[5]

Etymology

Behind the scenes

In the films, Shield Charms are used in nearly every duel shown, almost always used non-verbally and usually accompanied by a parry-like wand movement.

Also in the films, Shield Charms are shown to be able to deflect material objects such as arrows which were shot using a bow. Also it has shown to be able to withstand dragon fire from a Hungarian Horntail as seen in Harry Potter and the Deathly Hallows:Part 1 The Video Game.

The book depicts the Shield Charm as only being capable of repelling "minor to moderate curses and hexes", although Harry Potter uses it to block the worst effects of Antonin Dolohov's curse in the Department of Mysteries. However the film implies the Shield Charm to be significantly more powerful in that Harry is able to use it to completely deflect powerful curses cast by Voldemort himself.

In the early video games, Expelliarmus functions as a shield charm, due to a lack of enemies to Disarm. In these games, Protego is absent.

In the books Protego is also able to keep two quarreling wizards from going at each other when a shield is cast between them.

In Harry Potter and the Deathly Hallows: Part 2, Protego is shown several times to be able to block the Killing Curse. Harry blocks multiple Killing Curses from Voldemort during their final duel and Bellatrix Lestrange blocks four Killing Curses while duelling Molly Weasley. According to the books this is incorrect as the Killing Curse is "unblockable" which is the main reason for its particular infamy, but within the context of the films the fact is never mentioned. As the Killing Curse would instantly end any duel if it were unblockable, this might just be done for dramatic effect and for longer duels.